Affects a Windows OS component used broadly in enterprises; local privilege escalation to SYSTEM can enable full host compromise and is relevant to all IT teams.
CVE-2026-69918
Local privilege escalation via heap overflow in Windows Core Messaging.
Is CVE-2026-69918 being exploited?
Not confirmed. CVE-2026-69918 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.36% probability of exploitation in the next 30 days.
How severe is CVE-2026-69918?
CVE-2026-69918 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-69918?
Yes. A fix has been recorded for CVE-2026-69918. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-69918 affect?
CVE-2026-69918 affects Microsoft Windows - Core Messaging component, Windows client and server versions (see MS advisory). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-69918?
Install Microsoft update immediately; restrict local access and monitor endpoints.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local authorized attacker can exploit a heap buffer overflow to elevate privileges (potential SYSTEM), enabling full host compromise.
Immediate action required
- affected>= 10.0.14393.0 and < 10.0.14393.9612
- affected>= 10.0.17763.0 and < 10.0.17763.9376
- affected>= 10.0.19044.0 and < 10.0.19044.7807
- affected>= 10.0.19045.0 and < 10.0.19044.7807
- affected>= 10.0.22631.0 and < 10.0.22631.7652
- affected>= 10.0.22631.0 and < 10.0.22631.7652
- affected>= 10.0.26100.0 and < 10.0.26100.9711
- affected>= 10.0.26200.0 and < 10.0.26200.9711
- affected>= 10.0.28000.0 and < 10.0.28000.3231
- affected>= 10.0.26300.0 and < 10.0.26300.9711
- affected>= 10.0.14393.0 and < 10.0.14393.9612
- affected>= 10.0.14393.0 and < 10.0.14393.9612
- affected>= 10.0.17763.0 and < 10.0.17763.9376
- affected>= 10.0.17763.0 and < 10.0.17763.9376
- affected>= 10.0.20348.0 and < 10.0.20348.5761
- affected>= 10.0.26100.0 and < 10.0.26100.33650
- affected>= 10.0.26100.0 and < 10.0.26100.33650
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.